1891961 has 4 divisors (see below), whose sum is σ = 1953024. Its totient is φ = 1830900.

The previous prime is 1891951. The next prime is 1891969. The reversal of 1891961 is 1691981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1691981 = 103 ⋅16427.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1891961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1891969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30485 + ... + 30546.

It is an arithmetic number, because the mean of its divisors is an integer number (488256).

2^1891961 is an apocalyptic number.

It is an amenable number.

1891961 is a deficient number, since it is larger than the sum of its proper divisors (61063).

1891961 is an equidigital number, since it uses as much as digits as its factorization.

1891961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61062.

The product of its digits is 3888, while the sum is 35.

The square root of 1891961 is about 1375.4857323869. The cubic root of 1891961 is about 123.6813052743.

The spelling of 1891961 in words is "one million, eight hundred ninety-one thousand, nine hundred sixty-one".